Huge generators would operate in waters over a thousand feet deep.

The US and UK last week announced plans to develop enormous floating offshore wind turbines that can be deployed in much deeper waters and further out to sea.

By being freed of the towers that would usually tether offshore wind turbines to the seabed, floating turbines are not restricted to the usual 60-meter (200-foot) depth limit, and instead can be located in waters several hundred meters deep. Not only does this increase the areas of sea and ocean that can be harvested for wind, it grants access to faster and more reliable winds. And because wind turbines can be located further from the coast, they can be positioned beyond the sight of inland communities that may be less than impressed by the insertion of a wind farm into their scenic coastal view.

Last week Energy Ministers from the world's 23 largest economies met in London at the Clean Energy Ministerial co-chaired by US and UK Energy Secretaries Steven Chu and Edward Davey. In a statement issued ahead of the event, Davey announced that both the US and UK would be "making funding available," and described the two countries as being "determined to work together to capitalise on this shared intent."

Though couched in rather vague language, the statement does go into more detail as to the funding available. The UK's Energy Technologies Institute (ETI) is currently commissioning a £25 million ($41 million) floating demonstrator project. Selected participants will be invited to submit concepts of a floating wind turbine between 5 and 7 megawatts (MW) capacity. The winner will be asked to produce a working prototype to be installed by 2016. In the meantime, the ETI is narrowing down sites that could host the demonstrator. The additional waters opened up by floating wind technology allow access to hundreds of of gigawatts of additional wind resources. The UK's offshore wind potential has been calculated at 2200GW, which is thought to be about a third of Europe's total.

Meanwhile, the US Department of Energy has announced a $180 million "funding opportunity" for four offshore wind demonstration projects, though none is explicitly allocated for floating wind technology. Despite an estimated 4150GW of offshore wind potential, the US has no offshore wind infrastructure as yet, and floating technology may further the cause if NIMBYists can be persuaded that turbines will be placed out of sight and earshot.

Though floating wind turbines do exist, the cautious research-led approach adopted by the US and UK makes sense when you look at the scale of the task they've taken on. Wind turbines over 5MW in capacity are enormous: Enercon's 7.5MW E-126 inland turbine has a rotor diameter of 126 meters (413 feet).

To date, the largest floating wind turbine that has been installed is Norway's 2.3MW Hywind which has a rotor diameter of 82 meters (270 feet). The fact that its development cost is $62 million raises questions about whether the investment earmarked by the US and the UK will be enough to produce a stable floating turbine with more than double that capacity.

The form that the potential floating turbines will take hasn't been decided, but the most likely design is that individual turbines will effectively form vertical spar buoys, each moored by several catenary cables weighted at the ends. This would effectively be an enlarged version of the system used to moor the Hywind turbines—which actually employs additional 60-ton weights at the middle of each catenary cable in order to provide extra tension. Indeed, the next stage of the Hywind project hopes to apply the principle to a 5MW turbine in waters 320 meters (1,000 feet) deep—Norway has large-scale floating wind ambitions too.

An alternative means of mooring would be to adopt a tension-leg system, commonly used on offshore oil platforms since the 1980s. Something like an inverted pendulum, a tension-leg system would see a turbine mounted on a highly buoyant platform with steel tendons stretching vertically down to the sea bed. Research by MIT and the National Renewable Energy Laboratory suggests that 5MW turbines should be feasible at depths of up to 200 meters (650 feet).

The idea of multiturbine pontoons has additionally been, er, floated, but there are fundamental concerns about the cost of such systems, as well as their ability to withstand the extreme forces floating wind turbines would face during extreme weather.

Offshore wind plans are by no means restricted to the US and Europe. The Fukushima Recovery Floating Wind Farm Pilot Project confirmed by the Japanese government last month will initially consist of a 2MW turbine, to be joined by two 7MW turbines by 2016. And by 2020 the Marubeni Corporation plans to build a 1GW floating wind installation off Japan's northern coast, partly funded by the country's tsunami recovery budget. If it goes ahead, the scale of the wind farm would eclipse any sort of offshore wind farm currently in existence or under construction, though much bigger installations are in development, including a 9GW offshore farm at Dogger Bank off England's east coast.

85 Reader Comments

I can see it now, migrating birds see a giant island while crossing the Atlantic and decide to take a pit stop. Carnage ensues. It's like a bird magnet.

It would probably be "carnage" the first year or two. But as the smarter birds avoid the rather obvious blade thingys they will survive and produce smart offspring as well. Behold, evolution in action.

That's no good. We need to dumb down the birds so they're easier to hunt if needed. No need to give those below us on the food chain weapons for an arms race when we're sitting happily at the top.

I've an idea to add some additional generating capacity to nearly any off-shore wind mill. The towers are are essentially hollow tubes. Allow the ocean to partially flood the tube and place exhaust vents near the top of the tube. Place a wind turbine vertically, mid-way up the tube. The turbines rotors should be designed in such a way that no matter which direction the wind flows across them, they always rotate in the same direction (I've seen this done but am not sure how it is done - maybe it's just an airfoil). As the sea swells raise and lower the water level in the base of the tube, a column of air is moved up and down the tube causing the rotor to spin, generating current in the turbine. This may not be suitable for the floating turbines discussed in this article but it seems like it could for towers that are moored to the seafloor.

Fox news reported that these things add to the global warming issue–a problem they have flat out denied in the past. My small brain doesn't know what to think about this. Wouldn't it be better to set up deep sea drilling that have a much higher safety rating than these turbines and a reduced environmental impact?

I'd like to reply, but you can't seem to write a coherent thought for me to really understand you. Are you saying that deep sea oil drilling and offshore wind turbines are mutually exclusive? Are you saying that wind turbines are unsafe? Which ones, the ones they are trying to invent with this funding? Are you saying that floating offshore wind turbines add to global warming, or to the global warming ISSUE?

That was a bit aggressive. He said that Fox news claimed that wind turbines contribute to climate change; climate change is something that Fox news is somewhat notorious for outright denying. Ergo, Fox news can't keep their story straight.

Regarding drilling vs turbines, Sgt: Drilling requires something to drill to, so it's more location-dependent than wind turbines. Further, planet-bound petroleum is a finite resource, whereas the kinetic energy of wind derives from solar, making it effectively infinite. So as whquaint pointed out, while they are not mutually exclusive, the point here is to get the new tech rolling. Your suggestion that it's better to stick with off-shore drilling is akin to suggesting that these new-fangled automobiles are unproven and dangerous and we should stick with horses.

Eider wrote:

craigdolphin wrote:

Interesting. The obvious environmental concern would be for seabirds like petrels and albatross.

In many places environmental assessments on bird and bat populations are required for construction of new wind farms, and there have been several studies on this topic though the conclusions are still up for grabs. The general consensus seems to be that the habitat disturbance due to the presence, construction and maintenance of the farm will cause more harm than direct collisions with the towers. Making sure that wind farms are not placed near critical nesting habitat or migratory pathways is considered best practice right now (which might seem like common sense from a biology standpoint). There is a fair amount of information out there, even on Google, if you are interested.

While that seems wise, wouldn't chicken wire or something similar prevent the majority of the direct collisions, without significantly reducing the airflow? Can't hurt to prevent those, even if they're not as harmful.

Your'e not serious, right? Did you read how large the diameter of these things are? You are not enclosing a 400+ foot turbine in chicken wire. Seriously though birds are going to be a problem for this technology. Some early installations were placed in 'high wind' locations which were also in hawk/eagle migration routes because they like the winds too, to boost them to altitude where they can soar for miles with little effort. More consultaion with biologists and better site selection needed.

If you chained the wind turbines you could also get energy from the up down movement of the waves on the chain, this is relatively simple to convert into circular motion and thus power. Doing so efficiently might take some time but its all wasted energy otherwise.

Fox news reported that these things add to the global warming issue–a problem they have flat out denied in the past. My small brain doesn't know what to think about this. Wouldn't it be better to set up deep sea drilling that have a much higher safety rating than these turbines and a reduced environmental impact?

I'd like to reply, but you can't seem to write a coherent thought for me to really understand you. Are you saying that deep sea oil drilling and offshore wind turbines are mutually exclusive? Are you saying that wind turbines are unsafe? Which ones, the ones they are trying to invent with this funding? Are you saying that floating offshore wind turbines add to global warming, or to the global warming ISSUE?

That was a bit aggressive. He said that Fox news claimed that wind turbines contribute to climate change; climate change is something that Fox news is somewhat notorious for outright denying. Ergo, Fox news can't keep their story straight.

Regarding drilling vs turbines, Sgt: Drilling requires something to drill to, so it's more location-dependent than wind turbines. Further, planet-bound petroleum is a finite resource, whereas the kinetic energy of wind derives from solar, making it effectively infinite. So as whquaint pointed out, while they are not mutually exclusive, the point here is to get the new tech rolling. Your suggestion that it's better to stick with off-shore drilling is akin to suggesting that these new-fangled automobiles are unproven and dangerous and we should stick with horses.

Eider wrote:

craigdolphin wrote:

Interesting. The obvious environmental concern would be for seabirds like petrels and albatross.

In many places environmental assessments on bird and bat populations are required for construction of new wind farms, and there have been several studies on this topic though the conclusions are still up for grabs. The general consensus seems to be that the habitat disturbance due to the presence, construction and maintenance of the farm will cause more harm than direct collisions with the towers. Making sure that wind farms are not placed near critical nesting habitat or migratory pathways is considered best practice right now (which might seem like common sense from a biology standpoint). There is a fair amount of information out there, even on Google, if you are interested.

While that seems wise, wouldn't chicken wire or something similar prevent the majority of the direct collisions, without significantly reducing the airflow? Can't hurt to prevent those, even if they're not as harmful.

Your'e not serious, right? Did you read how large the diameter of these things are? You are not enclosing a 400+ foot turbine in chicken wire. Seriously though birds are going to be a problem for this technology. Some early installations were placed in 'high wind' locations which were also in hawk/eagle migration routes because they like the winds too, to boost them to altitude where they can soar for miles with little effort. More consultaion with biologists and better site selection needed.

I was under the impression that thermals lifted gliding birds to great heights for little or no energy output I have never heard of high wind acheiving the same effect in birds of prey.

There are two main sources of lift both birds and glider pilots use, thermals and ridge lift. When wind encounters a mountain it goes up and over the mountain. If you are above the windward slope in the right spot, then you can get a really good ride up. There are also lee waves that occur past the mountain, which were used to set the glider altitude record of 15445 meters.

High wind locations are usually not just where the winds are strong because of the latitude and other large scale geological features, but because there is a local funnel formed because of mountains, which means there is usually good opportunities for ridge lift.

I don't see any mention of how they plan to get the power from the turbines to land.

Um... cables?

Saying "cables" is all well and good. But are they cables dropping down a thousand feet and then following the seafloor to land? Are the shallow cables floating just deep enough to hopefully not get cut by passing boats? What happens to these cables in bad weather? When the towers are floating, the dynamics are different, and inquiring minds want to know the details.

Well not an expert on cables here but considering these are proposed as being tethered to the seafloor I imagine the power cable could run down the tether to the anchor then along the seabed to the shore. Undersea cables are common so I imagine this isn't really the difficult part to figure out.

So how fast are the currents say 50 or 100 meters below the surface? Would it be at all practical to couple wind turbines up top with ocean current turbines down under? The biggest ( ) obstacle I can think of are the large under-sea mammals running into them. That alone might make it unfeasable but it might be worth looking into.

If you chained the wind turbines you could also get energy from the up down movement of the waves on the chain, this is relatively simple to convert into circular motion and thus power. Doing so efficiently might take some time but its all wasted energy otherwise.

There maybe a dozen main designs for wave powered generators in testing around the world. The Pelamis brand is pretty close to what you are describing. Combining offshore wind with wave, tidal, and current based generators, as well as managing the areas as fish hatcheries is probably what most countries will end up doing.

Fox news reported that these things add to the global warming issue–a problem they have flat out denied in the past. My small brain doesn't know what to think about this. Wouldn't it be better to set up deep sea drilling that have a much higher safety rating than these turbines and a reduced environmental impact?

I'd like to reply, but you can't seem to write a coherent thought for me to really understand you. Are you saying that deep sea oil drilling and offshore wind turbines are mutually exclusive? Are you saying that wind turbines are unsafe? Which ones, the ones they are trying to invent with this funding? Are you saying that floating offshore wind turbines add to global warming, or to the global warming ISSUE?

That was a bit aggressive. He said that Fox news claimed that wind turbines contribute to climate change; climate change is something that Fox news is somewhat notorious for outright denying. Ergo, Fox news can't keep their story straight.

Regarding drilling vs turbines, Sgt: Drilling requires something to drill to, so it's more location-dependent than wind turbines. Further, planet-bound petroleum is a finite resource, whereas the kinetic energy of wind derives from solar, making it effectively infinite. So as whquaint pointed out, while they are not mutually exclusive, the point here is to get the new tech rolling. Your suggestion that it's better to stick with off-shore drilling is akin to suggesting that these new-fangled automobiles are unproven and dangerous and we should stick with horses.

Eider wrote:

craigdolphin wrote:

Interesting. The obvious environmental concern would be for seabirds like petrels and albatross.

In many places environmental assessments on bird and bat populations are required for construction of new wind farms, and there have been several studies on this topic though the conclusions are still up for grabs. The general consensus seems to be that the habitat disturbance due to the presence, construction and maintenance of the farm will cause more harm than direct collisions with the towers. Making sure that wind farms are not placed near critical nesting habitat or migratory pathways is considered best practice right now (which might seem like common sense from a biology standpoint). There is a fair amount of information out there, even on Google, if you are interested.

While that seems wise, wouldn't chicken wire or something similar prevent the majority of the direct collisions, without significantly reducing the airflow? Can't hurt to prevent those, even if they're not as harmful.

Your'e not serious, right? Did you read how large the diameter of these things are? You are not enclosing a 400+ foot turbine in chicken wire. Seriously though birds are going to be a problem for this technology. Some early installations were placed in 'high wind' locations which were also in hawk/eagle migration routes because they like the winds too, to boost them to altitude where they can soar for miles with little effort. More consultaion with biologists and better site selection needed.

I was under the impression that thermals lifted gliding birds to great heights for little or no energy output I have never heard of high wind acheiving the same effect in birds of prey.

Birds will migrate when winds are favorable. A good tailwind is essential for birds to be able to travel the vast distances they need with the limited energy resources they have during migration. If a location tends to have consistently favorable winds then you can expect a lot of birds will use the location for migration. If you put a wind farm in a location that lots of birds use for migration, then you put a giant hazard in front of them.

I find it ironic that the liberals who shove renewable energy down everyone's throats are the ones who don't want offshore wind resources that will obstruct their oceanfront views.

Without having done the research, I'm going to hazard a guess that the rich folks with oceanfront views are overwhelmingly conservative.

Take a look at a map of our biggest coastal cities. Not only do rich folks like the windier exurban coasts, they often like to do recreational sailing there, too. At precisely the best locations for sustainable electricity for our biggest cities. Of course, that won't be a problem once rising seas flood their cottages.

I've an idea to add some additional generating capacity to nearly any off-shore wind mill. The towers are are essentially hollow tubes. Allow the ocean to partially flood the tube and place exhaust vents near the top of the tube. Place a wind turbine vertically, mid-way up the tube. The turbines rotors should be designed in such a way that no matter which direction the wind flows across them, they always rotate in the same direction (I've seen this done but am not sure how it is done - maybe it's just an airfoil). As the sea swells raise and lower the water level in the base of the tube, a column of air is moved up and down the tube causing the rotor to spin, generating current in the turbine. This may not be suitable for the floating turbines discussed in this article but it seems like it could for towers that are moored to the seafloor.

Thoughts?

Look up the wave generator design caked "Oscillating Water Column". It's close to what you're describing. I don't think they try to combine the airflow from the water Column with the airflow of a wind turbine, just use the water Column airflow by itself. There has been a little speculation about combining wave and offshore wind generators at either the same platform or at least the same farm/array. There are both problems and opportunities with combining these operations this closely. It's definitely worth continuing development. Please keep thinking ideas like this over, and look up some sites on wave, tidal, current ... Hydro-kinetic... Power.

This might sound like a stupid question but I'll ask anyways. I understand physics, but not how the environment work, or power generators, or weather, etc, etc.

There is no such thing as a free lunch, and what I mean by that in this context is energy is only ever converted, not created (conservation of energy) Wind generators simply take the energy from moving air particles and converts them to electricity, to do so the air particles slow down. Knowing that, I wonder what the impact would be of, essentially, slowing the wind down?

And on a similar note, why not use generators in places where we don't want the energy, where we instead erect barriers instead? Like ocean waves that are eroding cliff sides, why not employ tidal wave generators so the waves impact with less energy? or dissipate heat instead of trying to convert it back to energy (since heat is energy)? Is it just to cost prohibitive to capture the energy instead of blocking it?

It's not a stupid question; you just need to consider the magnitude of the effects involved.

For the case of wind and tidal, the amount of energy nature provides (thanks to the sun's heat and moon's gravitational pull) is so vastly higher than any realistic amount we can harvest that it can safely be considered "free" energy.

Consider the amount of energy required to move a gazillion tonnes of air over hundreds of kilometers. Now, consider the amount of energy required to spin a wind turbine. That should help to put things in perspective. The "xxx GW of wind energy available" figures are estimates based on the amount of energy that we could realistically harvest with modern technology, not the total amount of energy present in the system.

That should also answer your second question. Yes, wind turbines or tidal buoys will indeed reduce the amount of energy in the system (and thus the erosion caused), but by a vanishingly small amount.

"I can see it now, migrating birds see a giant island while crossing the Atlantic and decide to take a pit stop. Carnage ensues. It's like a bird magnet."

Throw a fake owl on there, problem solved.

Yeah. the Owl the natural predator of the albatross.

i see your point. it's a shark that is needed.

I'm thinking big cats. Perhaps a puma.

...riding a shark. And don't forget the lasers (which would be powered by the wind turbine).

Edit: wind turbines are not windmills.

During the beta for the last world of warcraft expansion, there were complaints that a certain dramatic part of the game was not 'epic enough'. So temporarily the developers added this: Epicus Maximus. It's an undead guy playing a skull guitar, riding a dinosaur, riding a shark (with lasers) powered by rockets. Fanart Arty version

While that seems wise, wouldn't chicken wire or something similar prevent the majority of the direct collisions, without significantly reducing the airflow? Can't hurt to prevent those, even if they're not as harmful.

Your'e not serious, right? Did you read how large the diameter of these things are? You are not enclosing a 400+ foot turbine in chicken wire. Seriously though birds are going to be a problem for this technology. Some early installations were placed in 'high wind' locations which were also in hawk/eagle migration routes because they like the winds too, to boost them to altitude where they can soar for miles with little effort. More consultaion with biologists and better site selection needed.

I'll agree that proper site selection (prevention) is better than a barrier (cure), but I fail to see how engineering some type of netting or fencing would be significantly more difficult than engineering the 400-foot diameter turbine itself.

There are quite a lot of ways to avoid harming birds with wind turbines, methods like radar tracking larger groups of birds and slowing/shutting down the turbines in the path, or using directional sound to scare the bird into changing course, and so on. The cost of this stuff is minuscule compared to the cost of the turbines themselves.

And as someone has said, no studies have actually totally shown that birds/bats are harmed by wind turbines, disturbance in building them is more damaging. Shit, buildings kill a ton of birds, but nobody is screaming about that.

Not to mention the amount of environmental study that goes into putting a wind farm up (or anything else) is stunning. We are on year 3 of environmental studies for one wind farm we are involved with, and there is at least 2 more years and a few million bucks of study to go. These things don''t just get thrown up there and left to turn animals into pink mist.

So how fast are the currents say 50 or 100 meters below the surface? Would it be at all practical to couple wind turbines up top with ocean current turbines down under? The biggest ( ) obstacle I can think of are the large under-sea mammals running into them. That alone might make it unfeasable but it might be worth looking into.

Water currents at 50-100 meters below the surface are close to zero in the general ocean. Only in special cases is there a current (funnel like coast lines, Golf stream, which is also much, much weaker st those depths).

Imagine the Ocean like a swimming pool where somebody with a hair dryer is blowing air against the surface of the water. One would get some water entrainment at the surface, but next to nothing further below.

This is the reason why you are not seeing a lot of activity behind water current turbines in oceans. Only in coastal vicinity is there a tidal current to draw from.

BTW to all of those worried about migratory birds, they generally migrate over land masses, not at sea. So the ones in Europe usually don't cross the Atlantic. Terns and other aquatic fowl do migrate over water but they also usually fly at much higher altitudes.

I used to work in the oil and gas exploration industry, California (largest consumer of fossil fuels per capita) forces oil rigs to be built and operated inside of buildings. Even rigs offshore are "hidden" behind fake building prosceniums when they are 5 to 6 miles off-shore. I worked on a land rig that was 4 miles from the Hollywood sign inside the city! NIMBY's liberal or otherwise are idiots. If you consume power or fossil fuels you should have to pay the cost and that should include the esthetics. I think they need a daily reminder of that cost, maybe they won't buy that freaking huge SUV or have the AC running at meat-locker temperatures!

i still dont fully understand why we dont just go full on nuclear... this wind/solar stuff is ridiculous

Ignorance from the right and left maybe. I don't have any specific issues with Windpower as it can be cost effective but none of these so called green solutions is a long term answer to the energy crisis. In fact government involvement in Wind technology should be seen as a waste of tax payer money as the technology is already mature and self sustaining.

Instead our tax dollars should be going to research into nuclear sources (both fission and fusion). To put it rather bluntly our society as a whole has gone stupid with respect to preparing the land for future generations. The planet will end up looking fairly pathetic covered in wind turbines and solar cells.

BTW to all of those worried about migratory birds, they generally migrate over land masses, not at sea. So the ones in Europe usually don't cross the Atlantic. Terns and other aquatic fowl do migrate over water but they also usually fly at much higher altitudes.

I used to work in the oil and gas exploration industry, California (largest consumer of fossil fuels per capita) forces oil rigs to be built and operated inside of buildings. Even rigs offshore are "hidden" behind fake building prosceniums when they are 5 to 6 miles off-shore. I worked on a land rig that was 4 miles from the Hollywood sign inside the city! NIMBY's liberal or otherwise are idiots. If you consume power or fossil fuels you should have to pay the cost and that should include the esthetics. I think they need a daily reminder of that cost, maybe they won't buy that freaking huge SUV or have the AC running at meat-locker temperatures!

Sadly people these days don't have a clue. They have no idea where their power comes from, their food or even their electronics. The bad part here is that these same people are easily manipulated or down right gullible. America could learn something from the Chinese and send these people out to the country to raise a little food, work an oil rig or otherwise endure some enforced enlightenment. It would be nice if such would work but you are dealing with etremely stupid and vain people.

With nuclear material, there's really nothing you can do with the waste product, other than store it somewhere and watch the half-life burn off over many years. If we could utilize it in some way shape or form, all the way up to the point where it's really a negligible health hazard, then we could look at nuclear energy as a full on solution.

TLDR: Nobody wants to glow in the dark.

While I'm not generally a fan of nuclear power, I think it's worthwhile to point out that reprocessing of fuel would reduce the waste significantly. But then you get into the problem of having weapons grade material more readily available.

If things continue along their present path, we may have no choice but to go with nuclear fission power. As many fans of the process point out. However, it's also possible that renewable power sources such as wind could buy us enough time to get to practical fusion. That would change everything.

With nuclear material, there's really nothing you can do with the waste product, other than store it somewhere and watch the half-life burn off over many years. If we could utilize it in some way shape or form, all the way up to the point where it's really a negligible health hazard, then we could look at nuclear energy as a full on solution.

TLDR: Nobody wants to glow in the dark.

While I'm not generally a fan of nuclear power, I think it's worthwhile to point out that reprocessing of fuel would reduce the waste significantly. But then you get into the problem of having weapons grade material more readily available.